Painted markings are commonly applied to driving surfaces in order to mark lanes, stopping positions, crosswalks, railroad crossings, shoulders, and school zones. Asphalt and concrete surfaces in parking lots and driving areas of shopping malls, hotels, and office parks are also commonly provided with painted markings to guide drivers to desired locations and to demarcate parking positions. Airports also include surfaces that have painted markings for identification and outlining of runways and taxiways. It is often the case that painted markings are located outdoors and are exposed to harsh environmental conditions.
Since these markings may be a critical component of roadway surfaces, it is desirable to make them bright in color and strongly adhered to the roadway surfaces so they will be clearly seen and will not degrade and be removed. Highway paints may be acrylic-based and can contain ingredients such as methyl methacrylate which make them much brighter and durable than normal paints. Lane markings that are hard to see may cause drivers to swerve into adjacent lanes or to in fact drive in a lane designated for oncoming traffic. As such, roadway markings are generally made in a robust manner and are long lasting.
Often times it is desired to remove roadway markings when roads undergo construction or traffic patterns are changed. Further, painted markings are removed in other instances such as when parking spaces in a parking lot are changed. Since highway markings are made of paint that is stronger and more firmly adhered to roadway surfaces than paints applied to common household surfaces, the removal of highway markings is challenging. One cannot use paint removal techniques suitable for household paint removal on painted roadway markings as these two paint applications are not similar to one another but are more apples to oranges in comparison.
Highway marking removal may be accomplished by grinding the painted markings off of the roadway surface. This method is successful in removing the painted markings but also results in significant damage to the asphalt or concrete making up the roadway surface. Another method of removal is to use ultra high pressure water blasting or abrasive blasting (for example sand blasting). These techniques may also create damage to the roadway surface, and with grinding are expensive, slow, and may also result in unpleasant scars on the roadway. Also, in the case of water blasting a large amount of water is generated. If the highway paint is lead based, this large amount of water must be disposed of using proper channels and cannot simply be allowed to drain off of the roadway. Disposal of large amounts of toxic water also increases the cost of the removal. As such, there remains room for variation and improvement within the art.
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the invention.